This invention concerns exercise, recreational and training devices utilizing a suspended or tethered inflatable ball, and more particularly, a punching bag and its suspension.
There are many common desiderata in the performance characteristics and construction of suspended or tethered game or exercise balls or bags but, for simplicity, the following discussion will be limited to punching bags, sometimes called striking bags, and their suspension.
The general form of the conventional punching bag is well known. An approximately pear-shaped bag is suspended from a rebound board or platform fixed at such height above the floor that an erect "boxer" can comfortably sustain a steady regular series of strikes (a volley) on the bag. Bag and board are designed to produce, in combination, a desired coefficient of restitution or "bounce" of the bag from the board. For typical conventional and professional punching bags, this bounce corresponds to a rebound to strike ratio range of between 3 and 6 to 1.
In a typical conventional bag an inflatable bladder is contained in a relatively stiff and heavy leather casing. Consistency of rebound characteristic is achieved in part by suspending the bag from the board by a short flexible suspension the lower end of which is attached with substantial rigidity to the bag casing. That is, the attaching element at the bag is substantially fixed with respect to the bag itself. Between this bag attachment point and the rebound board the flexible connection usually provides at least two effective hinge points. The suspension is not a simple swivel, so that the bag swings simply radially with respect to the board, but rather a compound hinge which permits the bag to "rock" as well as swing when struck, and also to rock relative to the rebound board upon impacting the board.
At the suspension attachment point the bag may be reinforced by inserting a domed or conical collar into the neck of the bag and lacing or clamping the bag neck over it. The collar then provides a relatively inflexible attaching point for the bag. See for example U.S. Pat. Nos. 600,777 Frazier, 758,279 Rhodes, 1,119,635 Reach, and 2,815,952 Glasberg.
The flexible suspension may include combinations of elements such as a ball swivel and loops or rings of metal or leather or may comprise a short cord of rubber or other flexible material. See for example Reach and U.S. Pat. Nos. 2,323,624 Schall, 2,548,089 Wycosky and 3,226,116 Klingler.
Conventional and professional punching bags are relatively heavy and expensive. Because of the forces and shock loads developed, even in normal use, mounting arrangements must be "heavy duty" so that the installation is essentially permanent and not readily made portable. To avoid damage to the hands boxing gloves must be worn. For these and other reasons the market for the conventional suspended punching bag is well defined and quite limited.
Some attempts had been made to make punching bag action available to a wider public, including children. But in general these were more successful in visual simulation of the conventional punching bag than in a functional re-production of its desirable characteristics as outlined above. See for example the punching bag included in a free standing exercise kit offered by the toy retailer Toys R' Us TM. See also Klingler. A related disclosure is that of the Goldberg's in U.S. Pat. Nos. 2,143,691 and 2,510,883. These describe floor mounted rather than suspended "punching bags" and consist simply of an inflated balloon clipped to the upper end of a flexible standard. There is no serious attempt to make a stiff connection of the balloon to the standard or to reinforce the balloon wall.
In general the action provided by known scaled down light duty or toy versions of punching bags had been disappointing particularly in their failure to provide a satisfactory volley action. A typical defect was their use of a soft, inelastic casing, of vinyl for example. Such casings, in lighter or toy punching bags, produced poor bounce, were relatively expensive and comparatively heavy.
The punching bag and suspension of Donohue (U.S. Pat. No. 4,953,852) overcomes many of the problems of the prior art and offers a light duty punching bag with good functional characteristics. Its success is based largely on the "integration" of a resilient bag with a suspension collar. The bag consists of two similar elastic envelopes, one inside the other, and the suspension collar is inserted in an opening of the outer bag so that, upon inflation, a skirt of the collar is trapped between the walls of the two elastic envelopes. The inflation neck of the inner bag is accessible through an orifice in the collar and is closed or sealed after inflation, for example by a clip. Although its performance is good Donohue does require two elastic envelopes or balloons and the arrangement for sealing of the inner balloon may not be convenient or durable for repeated inflation and deflation of the punching bag.